<textarea name="xmls" cols="38" rows="12" id="xmls" > 
    <?xml version="1.0" encoding="UTF-8"? > 
    <svc_result ver="1.0.0">
        <slia ver="1.0.0">
            <action>testing </action>
        </slia>
    </svc_result > 
</textarea > 
<input value="提交"  type="button" onclick="submiter();"/ > 

<script language="javascript" > 
//获取表单中的XML文档 
//提交给testSSS.asp，同时获取返回值 
//再把返回值填写到表单中 

function submiter(){ 
    //获取表单中的XML 
    var xml; 
    xml = document.getElementById("xmls").value; 

    //构造url 
    var url; 
    url = "testSSS.asp"; 

    //调用提交函数 
    //并获取返回的XML 
    sendXML(url,xml); 
} 
</script > 

 
 function sendXML(url,xml){  
  
 	var subURL;  
 	subURL = url+"?xml="+xml;  
  
 	var xmlobj;  
 	xmlobj=createxmlhttp();  
 	xmlobj.open("post",subURL, true);  
  
 	var rsText;  
  
 	rsText = "Nothing";  
 	xmlobj.setRequestHeader("Content-Type","application/x-www-form-urlencoded");  
 	xmlobj.onreadystatechange=function (){  
 		if (xmlobj.readyState==4){  
 			if(xmlobj.status==200){  
 				sendXML.rsText = xmlobj.responseText;  
 				alert(sendXML.rsText);//这里弹出的是responseText值  
 				//rsText = xmlobj.responseText;//这种办法也测试过，效果一样  
 				//alert(rsText);  
 			}  
 		}  
 	}; 
 	xmlobj.send(null);  
  
 	alert(rsText);//这里就变成了修改前的值：“Noting”  
 	return rsText;  
 }  
  
 function createxmlhttp()  
 {  
 	//create xmlhttp object  
 	xmlhttpobj = false;  
 	try{  
 		xmlhttpobj = new XMLHttpRequest;  
 	}catch(e){  
 		try{  
 			xmlhttpobj=new ActiveXObject("MSXML2.XMLHTTP");  
 		}catch(e2){  
 			try{  
 				xmlhttpobj=new ActiveXObject("Microsoft.XMLHTTP");  
 			}catch(e3){  
 				xmlhttpobj = false;  
 			}  
 		}  
 	}  
 	return xmlhttpobj;  
 }  
 

<?xml version="1.0" encoding="UTF-8"? > 
<svc_result ver="1.0.0" > 
    <slia ver="1.0.0" > 
        <action >back XMLS </action > 
    </slia > 
</svc_result >